Continuous brake for a window drive mechanism



March 6, 1962 T. E. LOHR 3,023,854

CONTINUOUS BRAKE FOR A WINDOW DRIVE MECHANISM Filed April 19, 1957 2Sheets-Sheet 1 Z/WL /W I! 17 2? 2/ 29%! W; N NT R BY 7 90/2745 651K022ATTORNEY March 6, 1962 T. E. LOHR 3,023,854

CONTINUOUS BRAKE FOR A WINDOW DRIVE MECHANISM Filed April 19, 1957 2Sheets-Sheet 2 i i INVENTOR.

$502220; (ZZ/Zz I 11 BY W Z w" m 3,023,854 coNnNUoUs BRAKE FOR A WINDOWnnrvn MECHANISM Thomas E. Lohr, Detroit, Mich., assignor to GeneralMotors Corporation, Detroit, Mich, a corporation of Delaware Filed Apr.19, 1957, Ser. No. 653,800 2 Claims. (Cl. 18883) This invention relatesto a window drive mechanism, and more particularly to a window drivemechanism for power operated vehicle ventilation windows.

The drive mechanism of this invention offers several distinct advantagesover presently known and used mechanisms. One advantage is in thearrangement of the gear mechanism and electric motor in a compactunitary assembly which may be mounted on the vehicle as a unit but maybe easily disassembled in various component parts for repairs withoutnecessarily removing the entire unit from the body.

Another advantage is in the axial thrust take-up means for the worm inthe worm and worm wheel drive of the gear mechanism. The axial thrusttake-up means accurately positions the worm so that there will be noslippage between the worm and worm wheel and yet takes up axial thrustin either direction during rotation of the worm.

A further advantage is in the frictional clutch means to hold the windowdrive shaft in any rotative position thereof upon non-operation of thepower operating means to thereby prevent forceful movement of the windowby the operator or otherwise. In past mechanisms, the frictional clutchmeans has often included a strap which engaged the drive shaft of thewindow and had its ends secured to the housing or support for themechanism. At least one end of the strap had to be adjustable in orderto adjust the frictional force with which the strap engaged the driveshaft. Since the area of contact between the strap and shaft wasrelatively small, the strap had to be held against the shaft with anextremely high force in order to hold the shaft in rotative position.This often caused undue wear of the shaft and extremely hard operationof the shaft by the power operating means.

The frictional clutch means of this invention includes a Bellevillespring which is slidably and rotatably mounted on the drive shaft andhas inner and outer edge portions bearing respectively against a washerfixed to the shaft and a bracket secured to the housing to therebyprovide the required frictional force between the drive shaft andhousing to hold the shaft in any rotative position. Since the springdoes not bear against the drive shaft, there is no possibility of unduewear of the shaft. In addition, although there is a large total area ofcontact between the spring and the bracket and washer, this area isequally distributed for less local wear and more effective distributionof the required frictional force.

Yet another feature of the invention is in the coupling means betweenthe mechanism drive shaft and the window drive shaft. The drive shaft ofthe mechanism is provided with an axially directed outwardly openingslot which receives a generally U-shaped spring clip. The opposite legsof the clip are provided with lateral legs which converge to defineopposite spaced openings of less extent than the width of the slot. Thewindow drive shaft is provided with a flattened end which is received bythe converging lateral legs of the clip to thereby couple the driveshafts. If the shafts are misaligned, the clip will allow thismisalignment and yet provide a driving connection therebetween. Also, ifaxial adjustment of one shaft relative to another is necessary in orderto couple the shafts after assembly, the clip allows this axialadjustment without disturbing the drive connection. Further, since theflattened end of the window drive shaft is of less width than the widthof the opening in the mechanism drive shaft, there is no need for anycritical manufacturing tolerances on either shaft, since the spring clipwill take up these tolerances.

Further advantages of the drive mechanism of this invention will bereadily apparent from the following specification and drawings wherein:

FIGURE 1 is a partial side elevational view of a vehicle body embodyinga window drive mechanism according to this invention;

FIGURE 2 is an enlarged sectional view taken on the plane indicated byline 22 of FIGURE 1, with parts thereof broken away for clarity ofillustration;

FIGURE 3 is a sectional view taken on the plane indicated by line 3-3 ofFIGURE 2;

FIGURE 4 is a view taken on the plane indicated by line 44 of FIGURE 2;

FIGURE 5 is a sectional view taken on the plane indicated by line 5-5 ofFIGURE 4; and

FIGURE 6 is an enlarged sectional view taken on the plane indicated byline 66 of FIGURE 4.

Referring now particularly to FIGURE 1 of the drawings, a vehicle 10includes a windshield 12, a windshield header 14 and a roof 16. A frontdoor 18 is hinged at its forward edge 20 on the vehicle 10 for swingingmovement between open and closed positions to provide access to thebody. A window frame 22 extends upwardly from door 18 to the roof 16 ofthe body and provides a support for a swingably mounted ventilationwindow 24 movable between a closed position, as shown, and an openposition transverse of frame 22, not shown. The ventilation window ismounted within a frame 26 which is pivotally secured to frame 22 by anupper pivot (not shown) and a lower pivot provided by a window driveshaft 28. The upper and lower pivots define the vertical axis ofswinging movement of the Window. The drive shaft 28 is rigidly securedto the frame 26 and journaled within door 18 so as to drive the window24 between open and closed positions upon operation of the window drivemechanism 30.

Referring now to FIGURES 2 through 6 of the drawings, the drivemechanism 30 for the window 24 will be described. A housing 32 includesan upwardly opening vertical bore 34 and a horizontal bore 36 whichopens to bore 34 at 38. As may be seen best in FIGURE 3, a worm 40 ispositioned within bore 36, with one end 41 of the worm shaft beingrotatably supported therein by a plain bearing 42 fixedly secured withinbore 36 adjacent one end thereof. The other end 43 of the worm shaft isof reduced diameter and is rotatably mounted within a plain bearing 44fixedly secured within a reduced portion 45 of bore 36 in engagementwith a shoulder 46. A reduced portion 48 of bore 36 immediately adjacentthe reduced portion 45 slidably receives a thrust member 50. The thrustmember 50 includes an intermediate circular member 52 of nylon or otherdeformable material which is provided with opposite metal end plates 54and 56 secured thereto. The end plate 54 engages the adjacent end 43 ofthe worm shaft and the end plate 56 engages an adjusting screw 58 whichis threaded within a threaded bore 60 of the housing and locates themember 50 in engagement with the end 43 of the worm shaft. A lock nut 62holds the screw 58 in any adjusted position.

As may be seen best in FIGURES 2 and 4, a bracket 64 is bolted at 65 tothe housing 32 and includes a spaced pair of laterally extendingapertured legs 66. An electric motor 63 is bolted at to each leg 66. Aresilient washer 7'2 is provided on each side of each leg 66 to providefor resiliently mounting the motor on the bracket and also to preventthe vibration of the motor being transferred to the door inner panelwhich supports the mechanism 30 as will be described. The armature shaft76 of the motor terminates in a slotted end 78 which is received withina similar shaped opening on a metal plate 30 to secure the armature ofthe motor to the plate. Plate 80 is bonded to a circular member 82 ofrubber or other elastomeric material. The end 41 of the Worm shaft isprovided with a bifurcated portion 84 which is received Within spacedopenings in member 82 to couple the Worm to the armature shaft of themotor.

As will be hereinafter described, the worm 40 drives a worm wheel whichis part of the gear drive train between the motor 63 and the Windowdrive shaft 28. It is desirable that the worm 40 be held against anyaxial movement so as to prevent any slippage between the helical threadof the worm and the teeth of the worm wheel. It is also desirable thatsome means be provided to take up axial thrust loads of the Worm ineither direction. It is further desirable to provide a resilienttorsional coupling between the worm and the armature shaft of the motorso that overtravel of the motor will not bend or break any of the partsof the gear drive train when the window has reached a limit position inits movement.

The member 82 of rubber or other elastomeric material provides theresilient torsional coupling between the armature shaft of the motor andthe worm and takes up any overtravel of the motor when the window hasreached a limit position. This member also acts to take up axial thrustof the worm 49 in the one direction towards the armature of the motor.Although the member 82 is of rubber or other elastomeric material, therubber or other material is of the type which is not readilycompressible so as not to be easily compressed under light axial thrustloads. Thus, the member 82 will accurately position the one end 41 ofthe worm shaft under axial thrust loads in the one direction and willprevent any appreciable axial shifting movement of the worm in the onedirection except under heavyaxial thrust loads.

The member 52 of nylon or other deformable material acts to accuratelyposition the other end 43 of the worm shaft and to take up any axialthrust loads of the worm in an opposite direction. Since nylon or othermaterials of this type are not easily deformable, light axial thrustloads do not result in any appreciable axial shifting movement of theworm in this opposite direction except under heavy axial thrust loads.Thus the combination of the coupling 82 and the member 52 act to take upaxial thrust loads in either direction and to accurately maintain theposition of the worm except under heavy thrust loads. The plates 54 and56 on either side of the member 52 act to distribute the thrust loads ofthe worm shaft and the load of the adjusting screw 58 uniformly over themember 52 to prevent local deformation.

A worm wheel 90, FIGURE 6, is provided with a central bore 92 havingopposite flattened portions receives a shaft 14 having similar oppositeflattened portions 9 to rigidly secure the worm wheel to the shaft. Theworm wheel meshes with the Worm 40 and is driven thereby. Shaft 94includes an end 98 of reduced diameter which is located and rotatablysupported by a plain bearing 100 fixed within a closed boss 1112 ofhousing 32. In addition, an annular rib 104 on the lower wall of bore 34of the housing provides a thrust bearing for the worm wheel. A cover 106fits over the opening of bore 34 and is provided with an apertured boss108 which opens to bore 34 and a rib 110 which is received within theopening of bore 34 to accurately position the cover in place. A plainbearing 112 mounted within boss 108 locates and rotatably supports theother end of shaft 94 which projects outwardly of the cover. The coveris bolted to housing 32 at 65 and also at 113.

A plain bearing 114 mounted within an apertured boss 116 of the coverlocates and rotatably supports one end 117 of reduced diameter of amechanism drive shaft 118. The portion 119 of larger diameter of thedrive shaft 113 is provided with opposite flattened sides 120 g of theshaft.

and is received within a central opening of the same shape in a sector122 to secure the sector to the shaft. The sector 122 meshes with apinion 124- which is fixed to shaft 94. As may be seen best in FIGURE 5,the cover 106 is provided with an upwardly extending lug 125 adjacentthe boss 116. The circumferentially spaced shoulders 126 of the sectorare engageable with opposite sides of the lug to act as limit stopsfixing the limit positions of the window.

As may be seen best in FIGURES 2, 5 and 6, a U- shaped bracket 128bolted to the housing 32 at 65 and 113 is provided with a flangedopening 130 which rotatably receives and locates the enlarged end 132 ofshaft 118. A washer 134 is provided with a central opening of the shapeof portion 119 of shaft 118 so as to be fixed thereto. A Bellevillespring 136 is slidably and rotatably mounted on portion 119 of shaft 118and has its outer and inner edge portions under compression againstbracket 128 and washer 134, respectively. The bearing spring provides africtional coupling between the shaft 118 and the drive mechanismhousing through bracket 128 so as to frictionally hold the shaft in anyrotative position as will be further described.

Since the Belleville spring 136 does not frictionally bear against theshaft 118, there is no possibility of undue Wear In addition, it will benoted that only the inner and outer edge portions of the spring bearagainst the washer 134 and the bracket 128 respectively, so that theimmediate area of contact between any portion of the edge portions ofthe spring and either the bracket or washer 134 is relatively small.However, the total area of frictional engagement is rather large. Inaddition, since these total areas of engagement of the inner and outeredge portions of the spring 136 are concentrically located, a moreeffective frictional force is provided to hold the shaft 118 in anyrotative position thereof.

Referring now particularly to FIGURES 2 and 6 of the drawings, theenlarged end 132 of shaft 118 is pro vided with a cruciform shaped slot140. A generally U-shaped spring clip 142 flts within opposite legs ofthe slot 14% and conforms substantially to the contour of the slotbetween these legs, as may be seen particularly in FIGURE 6. Each of theopposite legs 144 of the clip is resiliently connected to the basethereof so as to be biased outwardly against opposite end walls of theopposite legs of the slot 140. As may be seen best in FIGURE 2, each ofthe legs 144 is provided with a pair of converging legs 146 with theextremity of these legs defining an opening of less width than the widthof the opposite legs of the slot receiving the spring clip. In addition,the legs 146 join each of the legs 144 on a curved juncture so that thelegs 146 may be wedged between the opposite side walls of each of theopposite legs of slot 140 to additionally hold the clip in place.

As shown best in FIGURE 2 of the drawings, the lower end of the windowdrive shaft 28 is flattened to provide a flattened end portion 156 whichis slightly larger than the openings defined by the converging legs 146of the spring clip so as to be wedgingly received between the oppositepairs of legs. Since the legs 146 are resiliently connected to each ofthe legs 144, it is not necessary for the window drive shaft 28 to beaxially aligned with the mechanism drive shaft 113, since the legs 146will take up any misalignment between the shafts. In addition, as willbe described, the drive mechanism 31) is fixedly mounted on the doorinner panel below the window 24 and the lower end of the window driveshaft 23 may not terminate exactly at the base of the clip 142, asindicated in FIG- URE 6. However, even under such conditions, the springclip will still provide a driving connection between the mechanism driveshaft 118 and the window drive shaft 28. Thus there is no need for anysubstantial adjustment of the window drive mechanism 30 relative to theshaft 28 in order to adequately establish a driving connection betweenthe shaft of the mechanism.

As best seen in FIGURES 5 and 6, an angular mountmg bracket 151 includesa pair of laterally extending spaced legs 152 which receive the boss 102of housing 32 therebetween and are bolted at 65 and 113 to the drivemechanism. The mounting bracket 151 further includes a number ofthreaded bosses 154 which extend laterally thereto and are adapted tobear against the inner panel 156 of door 18, as best shown in FIGURE 2.Bolts 158 which extend through apertures in the inner panel and arethreaded within bosses 154 mount the drive mechanism on the door in aunitary assembly.

It will be noted that the component parts of the drive mechanism aresecured together solely by the bolts 65 and 113 so that the assembly maybe easily disassembled into its component parts without necessarilyremoving the entire unit from the door 18. If replacement or repairs arerequired for the motor 68, removal of the bolts 70 allows the motor tobe detached from the assembly. If any repairs are needed internally ofthe mechanism, removal of the bolts 65 and 113 allow the entire drivemechanism to be easily disassembled without removing the mountingbracket 151 from within the door.

Since the operation of the drive mechanism is believed to be apparentfrom the foregoing description, only a brief description of theoperation will be given. Upon operation of the motor 68 in the requireddirection, the worm 40 will drive the Worm wheel 90 and in turn rotatethe shaft 94. As the shaft 94 rotates, the pinion 124 will drive thesector 122 and in turn drive the mechanism drive shaft 118. Themechanism drive shaft will then drive the Window drive shaft 28. Whenthe window has reached a limit position, the engagement of either of theshoulders 126 of the sector 122 with lug 125 will fix the limitpositions of the window. When the window is in any stationary position,the Belleville spring 136 will act to prevent any forcible movement ofthe window to another position by the operator or other persons. Inaddition, since the window 24 may be disposed in one or more open positions transversely of the opening of frame 22, the Belleville spring136 will act to hold the Window in this position against any windresistance caused by movement of the vehicle.

Thus this invention provides an improved window drive mechanism havingseveral distinct advantages over pres ently known and used drivemechanisms.

What is claimed is:

1. In a window drive mechanism, the combination comprising, a support, ashouldered drive shaft including axially spaced portions of varyingdiameter, one of said portions being journaled on said support torotatably mount said shaft thereon, a shaft support member mounted onsaid support and rotatably supporting another portion of said shaft,drive gear means slidably and non-rotatably mounted on a further portionof said shaft adjacent said one portion thereof and being locatedthereon by said support, a friction washer slidably and non-rotatablymounted on said shaft and bearing against said drive gear means forrotation therewith, means on said another portion of said shaft adaptedto be operatively connected to a window pivot shaft, and a resilientaxially compressible spring washer slidably and rotatably surroundingsaid further portion of said shaft and having inner and outer peripheraledge portions bearing concentrictally against said friction washer andsaid shaft support member to frictionally hold said drive shaft andwindow pivot shaft in any rotative position thereof against movement.

2. In a window drive mechanism, the combination comprising, a support, ashouldered drive shaft including axially spaced portions of varyingdiameter, one of said portions being journaled on said support torotatably mount said shaft thereon, a shaft support member mounted onsaid support and rotatably supporting another portion of said shaft,drive gear means mounted on a further portion of said shaft adjacentsaid one portion thereof, a friction washer mounted on said furtherportion of said shaft between said shaft support member and said drivegear means and bearing against said drive gear means, said anotherportion of said shaft including an axially opening bore adapted toreceive an end of a window pivot shaft and be operatively connectedthereto, and a resilient axially compressible spring washer slidably androtatably surrounding said further portion of said shaft and havinginner and outer peripheral edge portions bearing concentrically againstsaid friction washer and said shaft support member to frictionally holdsaid drive shaft and window pivot shaft in any rotative position thereofagainst movement.

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